Pentagon Design Competition for Flying Submarine

I wonder if any one remembers the television series "Voyage to the Bottom of the Sea" from the early 60s?

In the second season of the series, the nuclear research submarine Seaview is refitted to carry a "flying sub" in a hangar under it's chin. The flying sub was a beautiful little thing that looked like a cross between a Ford Mustang and a manta ray, in Corvette yellow. As conceived, it had nuclear powered jet engines which worked just as well with water as with air, giving a top speed of mach 2 in flight and 60 knots submerged.

I rather doubt that DARPA will try anything quite so dramatic or ambitious, although considering the performance and endurance they are after, some sort of small reactor might well be their only option. It's tough to build engines that can breath both air and water. As I recall, there were a number of nuclear aircraft proposals floating around in 60s and 70s which looked workable, and the flying sub was at least plausible.

Havn't they got anything sensible to do?
"maintain its tactical advantage for future coastal insertion missions".
I just love those insetion missions ...don't you .

Del

Pentagon announces flying catheter for insertion into the Thames in order to keep an eye on those sneaky, shopkeeper debils in the Court of St, James.

I really don't think they will receive the "workable entry" by the December 1st Deadline.

The requirements for aircraft, ships and submarines are almost opposite.

Kind Regards....

How about a combined lighter than air - heavier than water design?
You could have a nice lever to switch between the two modes.

Del (exit monitor left hurrying to patent office)

A combination bathesphere / blimp?

Eggsagerly... Justs needs a nice brass and Mahogany lever to switch modes (I'm sure KrisDel^TM labs can sort out the minor details...

Hello Del the cat

Looking forward to some photos placed here, when KrisDel^TM labs have completed the flying submarine.

Kind Regards....

How come a creature like a Gannet (Bird species) exists?

This flies very well and is capable of diving vertically into the water, swim under water for a while chasing its prey (behave like a submarine) and breaks the surface of water to take off vertically and enter the aerial realm and flies off with a "tasty" meal. It is able to repeat this performance several times a day.

Will somebody be good enough to acknowledge that "Nature is the ULTIMATE guide"!!

Does it have a nice lever to switch between the two modes?? It is heavier than water, partially lighter than air!!

It uses its aerial attributes and adapt them for operating in an underwater environment. It also manages its respiratory and muscular systems to complete its mission. Also, it gets a lot of practice to improve its capability.

And I agree with you that nature is the ultimate guide. It been at it for billions of years either by evolution or intelligent design, your choice.

PS the DARPA project (which is currently on hold by Congress) is for a submersible aircraft (seaplane) not a flying submarine.

Thank you for the concurrence. What's the difference between a Flying Submarine (Required by Pentagon design competition) and a Submersible aircraft?

Based on the above mission profile and that it is a vehicle, it travels 99 percent of its mission distance as an aircraft and wing in ground effect craft (Type C WIG) and only 1 percent as a submersible. This why DARPA was requesting concepts for a Submersible Aircraft and not a Flying Submarine.

And as all engineers know we let the mission design the vehicle not the vehicle design the mission.

In nature terms, they are requesting a Gannet and not a Flying Fish.

Well, hell then.

Just dust off some of those old Russki ground-effect planes and caulk the windows shut, give that a try.

Thank you for a beautiful graphic presentation. It intrigues me as to why they call it a "Pentagon Design Competition for Flying Submarine?? and not Submersible aircraft??" Is it something to do with the correctness of the original posting??

The following link is to DARPA's proposers day presentation

http://www.darpa.mil/sto/solicitations/BAA09-06/files/Proposers_Day_Presentation.pdf

Please note title

Enjoy

Thank you again Mr.Gannet.The link has been very useful in getting clarity on the title.As informed in one of my earliest postings on this thread, I have a concept design for just such a craft, proposed by me as far back as 1964 to our Indian Navy. Unfortunately, my chief was wanting it to be published in our internal magazine! He had said that he'd take it up if there was a consensus. I could not aggree on such a "preposterous" requirement (in my opinion), as I had wanted it to be a "secret". I was also under considerable pursuation to part with the details which even to date (31 Jan 2010),46 years later, I am holding close to my chest. Now that these ideas have occurred elsewhere on the planet, I guess, there is no point in holding back, but to use the "reinforcement" available to progress the development, utilising exotic materials which have been discovered since, and available COTS.

Didn't the Brit's invent something that would satisfy this spec. back in 1965?

Hello Bricktop

Great TV series favourites in the earlier days were Stingray and Thunderbirds - Gerry Anderson.

Children these days are Media saturated, and do not appreciate the early shows, which led to developments in Movie special effects.

Kind Regards....

Ya, Sparkstation, I loved those shows. A while back, a local cable station replayed the entire Stingray and Thunderbirds series. Actually, my kids, (now young adults), and my grandson, (age 3), enjoyed the show.

To get back on topic, that's a pretty tall order. I would suspect the transition, from the air to the water, and vice versa, would be a real challenge. I would be very surprised if it ever really happens.

Supposedly Russia attempted to develop a flying submarine back in WWII.

Never got off the drawing board for some reason...

And here's one that DID get off the drawing board - at least for a little while...

http://1000aircraftphotos.com/Contributions/KleinBernhard/6559.htm

Wasn't there a movie where "The Three Stooges" (Curly, Larry and Moe) did this to fight off aliens.

It was very entertaining

Another example of fact imitating fiction.

phoenix911

Gentlemen, just a few thoughts on this subject. First of all, I have always believed that anything which can be conceived can be achieved. Secondly, this community has some of the finest, most intelligent, imaginative, unconstrained and uninhibited scientific, engineering and technical minds on the planet. The point is that the idea has been proposed, and if anybody can hatch out a workable concept for how it might be done, we can. Besides, it's already been done once.

Now assuming I'm not going to be laughed right off of this thread, it seems to me that the first issue is propulsion. And ideally, we'd like it to have engines that can push both air and water, rather than two completely separate drives.

I'm going to step way out on a limb and say that for the kind of performance that they want, let's make the thing nuclear. Now bear with me for a moment before you start laughing. Several years ago the U.S. Air Force tested a closed cycle nuclear turbofan quite successfully. Also, we've been using a sort of turbine propulsion on torpedoes for years. Why not some sort of dual cycle turbofan which runs at high speed in air and low speed in water, using nuclear power to provide the energy to drive it?

Of course we are going to need shielding, but this thing's going to be pretty big anyway, so why not?

So how 'bout it? Any takers?

Hello DrMoose

Your idea of a single propulsion unit for both water and air is neither efficient or practical.

The fan blade design is very different for water and air.

The fan blade design is also very different for high speed and low speed.

So as you might see, the useage of a single turbofan which may be used for both fluids at different speeds, is not possible.

This gets us back to propulsion units optimized for each fluid medium: air and water.

Now there, that'll save some erstwhile designer from travelling down a dead end path.

Kind Regards....

Hey Sparky!

I never meant the idea to be efficient or practical, only that it could be done. And with DARPA it doesn't have to be particularly efficient or practical, it just has to work. I posted that comment simply to stimulate discussion.

Hello again, DrMoose

Thank you for the info above.

Please accept this especially made wooden spoon, for further stirrings.

Kind Regards....

Hey Sparky !*Chuckle*

Just for the fun of it, think with me for a minute, K? How about this?

Lets say we design a nuclear powered ducted fan. We optimise it for operation in air. But, if we slow it way down, it should still be able to move water, shouldn't it? And that's all we're really after. As long as it can move water at low speed, it'll still be able to provide propulsion, however inefficiently, and since we're talking about a small nuclear reactor, we've pretty much got power to burn.

Granted we wouldn't want to hit the water with the thing spinning at 30,000rpm, but say we splash down, give it some time to cool off, then submerge and spin it up to say 100rpm? It would move water and provide motion to the craft. Maybe not so efficiently as a properly designed impeller or prop, but it seems to me that it'd still work.

BTW, did you ever see "Voyage to the Bottom of the Sea" in New Zealand? The Flying Sub was a pretty little thing.

Hello again, DrMoose

The "Ducted Fan" idea as you suggest just won't work satisfactorily.

Compare the different densities of air and water.

The requirements are opposites:

Water: Large slow fan - very strong and heavy to withstand effort of pushing liquid water.

Air: High speed multi-stage fan, light and strong to push a very fast stream of air through.

Anyway the military would be needing a craft which can effortlessly pass from water to air, back to water, back to air, back to water etc, all without any "stopping on the way" as you suggest.

At present the only craft to satisfy those requirements appears to be a "Flying Saucer" which operates on "inertial gravity wave technology".

Kind Regards....

But the question is, would it work at all? It seems to me it would. It would have to be heavier than we'd like to survive in the water, but it should still give us decent propulsion in both regimes.

Anyway, it seems to me that the whole point of this exercise is to start from the idea that it can be done, and then figure out how to do it. If a single type of engine isn't going to do it, what would you propose?

Just for what it's worth, I've been a Navy frogman, and the requirement of having to put down for a bit a hundred miles off-shore isn't too big of a problem, as long as we can get the rest of the way under water. Ten knots submerged would be good enough, though twenty knots would be better.

As far as the grav-wave craft, that is something I've been dreaming of just about forever. But then if we had tech like that, I'd be inclined to gather like minded people, say the membership of CR4?, and go elsewhere. (Have to make sure there was an equal number of men and women of course.) Nothing like a few dozen lightyears to separate oneself from the absurdities of this tired old globe.

"The Flying Sub was a pretty little thing."

And for those who missed it, here 'tis:

As I recall, it crash landed about every second time they flew it, but that was for dramatic license, not due to technical difficulties...

Instead of one vehicle, I envisioned it being two vehicles a Wing in Ground Effect (WIG)/Seaplane (similar to the Be-103) (Class C WIG) that is capable of carrying internally, launching and recovering the 8 man submersible.

Please allow me to correct myself. There were two nuclear jet engine programs, one by General Electric which was "direct air" and one by Pratt & Whitney which was "indirect air". The GE engines were the only ones which were successfully tested. I am not an aerospace engineer, so please forgive me if I butcher the terminology.

Obviously, the indirect air system would be the desired technology, since it would reduce or eliminate radioactive exhaust.

I have a concept design partially engineered (to demo the feasibility) for submission.In fact, I had designed the original version in the year 1964 as a young lieutenant in the Navy. With all the tremendous technological progress that the world has made since then to date, it becomes all the more realisable.

Please advise whom do I send it to.

D.Ramakrishna Naidu

DARPA will be spending $3M in 2010 for the following:

From 2010 DARPA RDT&E Budget Item Justification 0602702E

"Submersible Aircraft

(U) This program will combine the speed and range of an airborne platform with the stealth of an underwater vehicle by developing a vessel that can both fly and submerge. The project will exploit lightweight materials, unique dynamic structures and advanced propulsion systems to overcome the technical barriers to achieving this capability. If successful, the project will enable insertion and extraction of special operations and expeditionary forces at greater ranges, and higher speeds, in locations not previously accessible; with minimal direct support from additional military assets. The program goals are to demonstrate a vessel capable of multimodal operations (airborne, surface, and submerged) and that can easily transition between these modes.

FY 2010 Plans:

- Conduct concept designs studies and perform feasibility analysis in order to quantify extent of possible operational envelope.

- Identify key technology limitations and performance objectives that need to be overcome in order to achieve concept design."

I assume the $3 Million will be split three way; however, cannot find out which contractors have been downselected.

Does anyone know which contractor(s) are in the running?

calling it a flying submarine and not a submersible aircraft might just be a matter of american English, casual usage, or the writer wanted the headline to convey a certain image with more dramatic impact. See post #1.

I remember many years ago (45>) an inventor was on some television game show and he had a short film segment of his invention that appeared to be a submersible airplane.

Of course it's not hard to get a plane to submerge, the trick is getting it to surface.